This is a sensitive game, especially for us part timers. We form habits based on limited practice hours and probably even more on match play. IF you are taking a long term view towards improvement, it's best to do what you want to do better even if it costs you matches. The time spent doing things that don't contribute counts and you end up wondering why that short serve never gets more precise and lower under pressure (it may be technical, but it may also be because you spent the time you could have spent using it to beat players with other serves). Of course, if you are not training and are playing largely for fun, doing whatever you enjoy is best. Long serves do fit some games by the way but playing opponent specific table tennis is not going to get you far unless the plays you use are plays that you can give a basis in your overall growth.
2 of my non-TT instructors teach
"The 3 F's" (Fit, Fun, Functional) ... in the context of TT, the first 2 F's are key. In my TT playing, I find I have a lot of Fun playing, which helps me get Fit. My instructors point out that if the physical activity one does is not Fun, no matter how Fit or Functional it makes one, one may not continue it as it's not Fun.
At this stage of my playing, I have no desire to compete in a tournament. So, if I'm spending my time on TT for Fitness and Fun, I may as well look to Improve also. Keeps me at it. Along the way, I meet up with Friends and hopefully can present them a better Challenge and hope my game improves their game.
"
Iron sharpens iron."
I generally serve all my serves in my repetoire ... if i find one is a weakness for my partner... i will serve it a tad more not to win the match, but to help my partner improve. I mentioned in one of my previous AAR's that i always lose to a modern penholder at my club... played him 4x or so so far. He eats my side-top pendulum serve 90% of the time. One night after a match, despite language barrier, I showed him how to return it... since that time, we only had a chance to play each 1x... maybe next time, i'm just going to serve to him and see if he doesn't mind not playing a match and practice serve return.
Iron sharpens iron. We are all in this together.
Thank you NL for your reply ... provides more focus in my unretirement!